The Ink is Still Wet

Recommended for High School.

Introduction

SPRINGFIELD, September 10: Science has proven indispensable in solving yet another kidnapping case. This time, a special kind of fingerprint—a chemical fingerprint—proved to be the crucial clue in recovering the victim, 22-year-old Shawn Morgan, unharmed.

It was only in the last month that Morgan sold his design for the TrueMind artificial intelligence system to the United States government for $100 million. As fate would have it, a day later, Morgan vanished. When investigators forcibly entered Mr. Morgan’s apartment, they found it empty except for a ransom note written on a piece of computer paper. The note was written in black ink, and the handwriting varied in style, so police handwriting experts were at a loss to come up with a profile.

Objectives

Identify an unknown ink by its light absorbance characteristics.

Measure a solution's absorbance of different colors (wavelengths) of light.